Stake extracting apparatus



United States Patent Inventor Appl. No.

Filed Patented Assignee Frank T. Pisano Cherry Hill, NJ.

June 24, 1968 Dec. 29, 1970 l g i The United States of America asrepresented by the Secretary of the Army STAKE EXTRACTING APPARATUS 4Claims, 2 Drawing Figs.

U.S. Cl 254/30 Int. Cl E21b 19/00 Field of Search 254/29, 30,

175/(Inquired); 294/106, 113, 115

[ 56] References Cited UNITED STATES PATENTS 2,579,533 l2/l 951 Alger..254/30X 2,964,752 12/1960 Kapf 22:7/8

Primary E.taminerAndrew R. Juhasz Assistant Examiner-David R. MeltonAttorneys-Harry M. Saragovitz, Edward J. Kelly, Herbert Ber] and S.Dubroff ABSTRACT: As an abstract of the disclosure, the invention isdirected to a stake extracting arrangement having gas generating mediafor operating a piston :in a vertically oriented cylinder, with thelower end of the piston rod carrying a lifting hook arrangement forengaging a stake to be extracted.

- Preferably, a number of lift and lock devices are provided onrespective support legs which are connected with a cylinder supportplate and a spider, such that the lifting hook arrangement may beprepositioned vertically prior to operation.

PATENTEDuEcze I970 SHEET '2 OF 2 NK ISANO BY: A rAl I 5124 ATTORNEYS.

STAKE EXTRACTINGAPPARATUS more particularly to stake extractingequipment particularly adapted for facilitated removal of stakes thathave been in frozen earth, heavy clay, black asphalt, or the like forsecurely mounting heavy weapons, etc.

One of the objects of the invention is to provide stake removalapparatus having an adjustment mechanism by which the initial positionof the lifting hook arrangement can be selectively chosen for desiredstake engagement.

Another object of the invention is to provide such a removal apparatuswhich is of sturdy construction.

A further object of the invention is to provide such ap-, paratus whichin operation enables automatic release of an extracted stake.

These and other objects, features and advantages will become apparentfrom the following specification and accompanying drawings in which:

FIG. 1 is a partial sectional elevation view of a stake extractingarrangement embodying the principles of the invention.

FIG. 2 is a top plan view of the FIG. 1 structure.

As seen in FIG. 1, the stake to be extracted, upon completion of itssecuring function for a weapon mount at a desired location upon mostanyfonn of ground, terrain or even frozen earth 11, is surrounded by abottomplate 12 of the supporting structure portion of the stakeextracting appara tus, the bottom plate or ring 12 being appropriatelyaper tured to receive a plurality (preferably 3) of upstanding supportlegs 13. Each support leg I3 has a foot member 14'and stop plate 15which are held in substantial abutment with each other by retainingrings .or snap ring stops 16, 17 seated in vertically spaced peripheralgrooves provided in the respective leg 13. At the upper end of eachstandard 13' a similar retaining ring 18 provides an upper limit stopfor the suitable apertured cylinder plate 19 which is slidably adjustedto desired positions on standards 13 by respective lift and lockarrangements adjustable mounted thereon as will be hereinafter describedand oneof which being shown generally at 20. The cylinder plate 19 iscentrally apertured and threaded for mounting the threaded lower end ofvertical cylinder2l housing sealed piston head 22 whose dependent rod 23is slidably received by the cylinder plate O-ring 24 and backup ring 25.

The lower end of the piston rod 23 has lifting hook stop means 26threaded thereto and slidable carries a lifting hook arrangement support27 which overlies the stop means 26 and is appropriately slottedadjacent each of a plurality (preferably 3) of horizontally disposedpins 28 that correspondingly journal the apertured car 29 of a.respective pivotable lifting hook 30. Themain bodyportion 31 of eachlifting hook is offset outwardlyof itspivot pin 28 so that the hookcenter of gravity will-normally bias the hook inwardly, and the lower orhook portion 32 has an inclined flanged surface 33 to facilitate agrapnel engagement with a selected further inclined undersurface 34, 34onpreforrned peripheral flanges of stake 10.

Stem valve 35 has its housing threadedly secured in an enlarged tappedapproach or entrance 36 of a horizontal passage 37 in cylinder plate 19that is in fluid communication with the underside of piston head 22. Theforwardmost reduced portion of the stem valve housing has a plurality ofradial openings 38, 38 that intersect its central bore 39 to permitdelivery of generated pressure gas from aligned vertical passages 40 and41 in the cylinder plate and sealed adapter 42 suitably threadedthereto. The adapter 42 is appropriately fluid connected to a gasgenerating or cartridge chamber within a rifle firing mechanism oraction 43 whose stock has "been omitted or removed and whose barrel hasbeen replaced by the adapter 42. The rifle operating trigger 44,protected by guard 45, through an appropriate internal mechanisminitiates a cartridge delivered to the cartridge chamber by a suitablestake "feed mechanism as actuated by bolt handle 46. Valve stem 50,adjustably connected to the valve housing internal threads 51,

has a reduced forward end 52 terminating in a concavely recessed tip forholding steel ball 53against its seat in the valve housing at therearward end of" passage 39 during generated gas delivery to the piston22. By counterclockwise rotation of valve handle 55 the stem 50 can bewithdrawn to the extent permitted by stem collar, 56 and bleeder stemstop 57 carried by the valve housing, whereupon ball 53 may be unseatedto allow post-operational exhausting of pressure gas through passage 39,passageway 60 within the valve housing and surrounding the reduced stemportion 52, and exit port 61 provided in' the valve housing.

A spider support guide 64, normally overlying lifting hook support 27,has a central opening 65 to slidingly receive the piston rod 23, as wellas corresponding openings 66, 66 for slidablepositioning along thesupport legs 13.

Upon an abrupt termination of upward piston rod travel upon reaching asufficiently compressed fluid at the upper end of cylinder 21, as wellas the lifting hooks 30 whose upper flanges 70 have been physicallyraised by the lifting hook stop 26, the extracted stake will be tossedupwardly off the hook inclined surfaces 33, the lower surface of eachhook portion 32 being cammed outwardly by the upwardly facing flangesurface 71 of the released stake peripheral groove, and the liftingbooks '30 are thus freed to be thrown outward by their moments ofinertia about their pivots for completely releasing the stake. The"compressed fluid above the piston is vented to the By means of a pair ofbolts or securing mechanism (not. shown) on either side of eachsupportleg 13 as indicated by 3 pairs of securing screws 78, 78 (FIG.'2)a jack housing 80 having upper and lower bifurcated ear portions 81, 82is held integral with the cylinder plate 19. Each housing 80 has itsears 81,82 apertured so as to be slidably mounted upon its respectivesupport leg 13 and contains a corresponding lift and lock arrangement 20by virtue of which the-cylinder plate 19 and its associated parts mayall be vertically adjusted relative to the support legs. Each lower ear82 supports a compression spring 83 that surrounds its support leg 13and in turn supports aitiltably mounted first lock member 84. A secondtiltably mounted lock member 85 surrounds the leg 13 and is adapted toengage a dependent portion 86 of the upper ear portion 81. Member85integrally carries a substantially horizontally extending firstpivotpost87 upon which is journaled anintermediate link 88. Link 88integrally carries a horizontal second pivotpin or post 89 and a liftand'lock or jack handle or cam lever 90 has itsforward end 91 journaledupon the second pivot pin 89 and provided with 'a concavelike recess inits upper surface to normally accommodate the convex lower. contour oflink 88. With the handle 90 held free and spring 83 normally underapredetermined amount of compression, the spring 83 will maintain thefirst lock member 84 in an unlocked and untilted slidable conditionwhile urging it upwards into contact with the rolling ggntact lowersurface of jack handle forwardend 91. In thiscondi tion of the liftandlock arrangement, the second or upper lock member 85 is tilted in alockingposition. When handle 90 is depressed in a clockwise direction(FIG. 1) about its pivot 89, it will roll along and depress or tilt thefirst lock member 84 to a locking position, and its forward end 91 willengage and move link 88 and the pivot post 87 clockwise with handle 90about pivot 89, thus freeing second lock member 85 and. urging it andits associated parts upwardly to elevate cylinder plate 19 and itsassociated structures. Upon release of handle 90, it and theintermediate link 88 will return to their relative positions, permittingthe upper lock member 85 to return to a locking condition, and by virtueof which the first or lower lock member 84 will be freed for upwardmovement as urged by spring 83. Repeated operation of the lift and lockdevices 20 will provide the desired cylinder plate position, aspermitted by the effectiveness of springs 83, such that the lifting hookarrangement will have capably secured the stake thereto, prior toactuation of piston elevating trigger 44.

Various modifications, changes or alterations may be resorted to withoutdeparting from the scope of the invention as defined in the appendedclaims.

1 claim:

1. in a stake extracting apparatus having an elongated vertical cylinderand a sealed piston slidably mounted therein:

a cylinder plate having a central aperture for receiving and supportingsaid cylinder;

a plurality of support legs each having an upper end portion slidinglyreceived by said cylinder plate;

a piston rod having an upper end secured to said piston and a lower endcarrying a lifting hook arrangement;

a spider member having a plurality of openings and receiving each ofsaid piston rod and support legs, said spider guiding said piston rodand lifting hook arrangement;

a lift and dock device on at least one of said support legs engagingsaid cylinder plate; and

gas generating means on said cylinder plate and in fluid communicationwith said piston head, so constructed and arranged that verticaladjustment of said lift and lock device will enable prepositioning saidlifting hook arrangement to a predetermined initial location relative tosaid support legs.

2. The apparatus in accordance with claim 1 wherein said lift and lockdevice includes a housing having bifurcated and apertured ear portionsunitarily slidable upon its support leg, a compression spring resting onone of said ear portions and supporting a tiltably mounted first lockmember, a second tiltably mounted lock member adapted to engage theother of said ear portions, a substantially horizontally extending firstpivot post carried by said second lock member, a link having one portionjoumaled upon said first pivot post and carrying a second pivot post,and a cam lever having one end journaled upon said second pivot post andadapted to engage said first lock member and said link.

3. The structure in accordance with claim 1 in which said lifting hookarrangement comprises a lifting hook support member slidably mountedupon said piston rod below but adjacent said spider member and having aplurality of horizontally disposed pivot pins, a lifting hook pivotallymounted upon each pivot pin, each hook having an inner surface providedwith an elongated recess defining vertically spaced upper and lowerflange portions, said lower flange portion of each hook being defined byan inclined hooking surface for engaging a stake to be extracted, and alifting hook stop member secured to said piston rod lower end andadapted to engage said upper flange portions.

4. The structure of claim 1 wherein said gas generating means comprisesa rifle having a gas generating delivery passage and mounted on saidcylinder plate, a passageway in said cylinder plate in fluidcommunication with the undersurface of said piston, and a bleeder valvesecured to said cylinder seating against said passageway, said bodyhaving a longitudinal central passage in fluid communication with saidpassageway, radial port means communicating said central passage withsaid gas generating delivery passage, and an exhaust port for placingsaid central passage in fluid communication with an externalenvironment.

